Pre-Installation Checklist — Mysa for In-Floor Heating

Last updated: August 10, 2026

Before You Start

Complete this checklist before you begin any installation work. It takes 10 minutes and prevents costly mistakes.

Step 1: Verify Your Circuit Voltage

What you need: A voltmeter (available at hardware stores for $10–$20)

Check Your Breaker Type

Look at your electrical panel and find the breaker controlling your floor heating circuit:

  • Single-pole breaker (narrow, one switch) = 120V circuit
  • Double-pole breaker (wider, two switches connected) = 208V or 240V circuit

Confirm with a Voltmeter

  1. Turn off the breaker
  2. Set your voltmeter to AC voltage
  3. Turn the breaker back on
  4. Carefully touch the voltmeter probes to the breaker terminals (or ask an electrician to do this)

Expected readings:

  • Single-pole breaker: ~120V
  • Double-pole breaker: ~208V or ~240V
Important: If your voltmeter reading doesn't match your breaker type, consult a licensed electrician before proceeding.

Step 2: Verify Wattage Requirements

Your floor heating system has a wattage rating. Mysa for In-Floor Heating has maximum load limits:

Check Your Heating System

  • Find your floor heating system's wattage (on the mat, documentation, or manufacturer specs)
  • Write down the wattage: __________ W
  • Verify it's under the max for your voltage:
    • 120V system? Must be ≤ 1,900W
    • 208V single-phase system? Must be ≤ 3,328W (16A)
    • 240V system? Must be ≤ 3,800W
If your system exceeds these limits: Mysa cannot safely control it. Contact your heating system manufacturer or a licensed electrician for alternatives.

Step 3: Check System Compatibility

Mysa for In-Floor Heating works with electric heating systems only. Verify your system type:

Compatible Systems ✓

  • Electric in-floor heating mats
  • Under-tile heating systems
  • Electric heating cables
  • Radiant floor heating (electric)
  • Single-phase 120V, 208V, or 240V systems within the applicable load limit

Incompatible Systems ✗

  • Hydronic (hot water) in-floor systems
  • 24V heating systems
  • Three-phase 208V systems
  • Forced air systems
  • Heat pumps
  • Natural gas or oil heating systems
Important: If you have a hydronic (hot water) in-floor system, Mysa for In-Floor Heating will not work. These systems require different controls.

Step 4: Confirm Floor Sensor Location

Before installation, decide where your floor temperature sensor will go:

  • Sensor location planned: Choose a spot within 15 feet (4.5 meters) of your thermostat in the heated area
  • Protected placement: Ensure the sensor won't be damaged by foot traffic, furniture, or water
  • Good sensor location examples:
    • Under a floor tile or mat (covered, protected)
    • In a small conduit tube under the floor
    • Taped to the top of the heating mat in an inconspicuous area
    • Ask your floor heating manufacturer for their recommendation
Note: The included floor sensor is 15 feet long and works with 5K–40K Ohm resistance sensors. If you need a longer sensor, compatible sensors are available separately.

Step 5: Turn Off the Breaker

Before touching any wires:

  • Locate the breaker controlling your floor heating circuit
  • Switch it to OFF
  • Leave it off during the entire installation

Step 6: Verify You're NOT on a GFCI Circuit

Important: Mysa for In-Floor Heating has a built-in Class A GFCI that cannot be disabled. Installing it on an existing GFCI-protected circuit will cause false trips and prevent operation.

Installation Readiness Checklist

  • Voltage verified (single-phase 120V, 208V, or 240V)
  • Wattage confirmed (under the applicable maximum)
  • System compatibility confirmed (electric heating only)
  • Breaker switched off
  • Floor sensor location planned
  • Copper wiring verified
  • 2.4 GHz Wi-Fi confirmed

Need Help?

If you have questions about your electrical setup, contact install@getmysa.com.